Clean sap_router_portscanner

Hi @morisson,

In this pull request I'm treaning to cleanup for #1884. Feel free to review, comment, test, discuss anything. Once you feel comfortable feel free to land it into your repo and the original pull request https://github.com/rapid7/metasploit-framework/pull/1884 will be automatically updated.

* Test:

```
msf auxiliary(sap_router_portscanner) > run

[*] Scanning 127.0.0.1
[+] 127.0.0.1:3242 - TCP OPEN
[*] Scanned 1 of 1 hosts (100% complete)
[*] Auxiliary module execution completed

```

* Verbose mode:

```
msf auxiliary(sap_router_portscanner) > run

[*] Scanning 127.0.0.1
[-] 127.0.0.1:3204 - TCP closed
[-] 127.0.0.1:3205 - TCP closed
[-] 127.0.0.1:3203 - TCP closed
[-] 127.0.0.1:3208 - TCP closed
[-] 127.0.0.1:3207 - TCP closed
[-] 127.0.0.1:3201 - TCP closed
[-] 127.0.0.1:3200 - TCP closed
[-] 127.0.0.1:3206 - TCP closed
[-] 127.0.0.1:3202 - TCP closed
[-] 127.0.0.1:3209 - TCP closed
[-] 127.0.0.1:3240 - TCP closed
[-] 127.0.0.1:3230 - TCP closed
[-] 127.0.0.1:3264 - TCP closed
[-] 127.0.0.1:3250 - TCP closed
[-] 127.0.0.1:3258 - TCP closed
[-] 127.0.0.1:3223 - TCP closed
[-] 127.0.0.1:3280 - TCP closed
[-] 127.0.0.1:3222 - TCP closed
[-] 127.0.0.1:3227 - TCP closed
[-] 127.0.0.1:3232 - TCP closed
[-] 127.0.0.1:3277 - TCP closed
[-] 127.0.0.1:3249 - TCP closed
[-] 127.0.0.1:3225 - TCP closed
[-] 127.0.0.1:3270 - TCP closed
[-] 127.0.0.1:3292 - TCP closed
[-] 127.0.0.1:3235 - TCP closed
[-] 127.0.0.1:3215 - TCP closed
[-] 127.0.0.1:3266 - TCP closed
[-] 127.0.0.1:3273 - TCP closed
[-] 127.0.0.1:3234 - TCP closed
[-] 127.0.0.1:3260 - TCP closed
[-] 127.0.0.1:3290 - TCP closed
[-] 127.0.0.1:3244 - TCP closed
[-] 127.0.0.1:3217 - TCP closed
[-] 127.0.0.1:3228 - TCP closed
[-] 127.0.0.1:3243 - TCP closed
[-] 127.0.0.1:3274 - TCP closed
[-] 127.0.0.1:3212 - TCP closed
[-] 127.0.0.1:3283 - TCP closed
[-] 127.0.0.1:3284 - TCP closed
[-] 127.0.0.1:3287 - TCP closed
[-] 127.0.0.1:3271 - TCP closed
[-] 127.0.0.1:3239 - TCP closed
[-] 127.0.0.1:3229 - TCP closed
[-] 127.0.0.1:3297 - TCP closed
[-] 127.0.0.1:3220 - TCP closed
[-] 127.0.0.1:3218 - TCP closed
[-] 127.0.0.1:3224 - TCP closed
[-] 127.0.0.1:3275 - TCP closed
[-] 127.0.0.1:3282 - TCP closed
[-] 127.0.0.1:3236 - TCP closed
[-] 127.0.0.1:3299 - blocked by ACL
[-] 127.0.0.1:3213 - TCP closed
[-] 127.0.0.1:3286 - TCP closed
[-] 127.0.0.1:3285 - TCP closed
[-] 127.0.0.1:3226 - TCP closed
[-] 127.0.0.1:3263 - TCP closed
[-] 127.0.0.1:3291 - TCP closed
[-] 127.0.0.1:3294 - TCP closed
[-] 127.0.0.1:3269 - TCP closed
[-] 127.0.0.1:3281 - TCP closed
[-] 127.0.0.1:3268 - TCP closed
[-] 127.0.0.1:3237 - TCP closed
[-] 127.0.0.1:3255 - TCP closed
[-] 127.0.0.1:3298 - TCP closed
[-] 127.0.0.1:3272 - TCP closed
[-] 127.0.0.1:3216 - TCP closed
[-] 127.0.0.1:3289 - TCP closed
[-] 127.0.0.1:3238 - TCP closed
[-] 127.0.0.1:3221 - TCP closed
[-] 127.0.0.1:3293 - TCP closed
[-] 127.0.0.1:3214 - TCP closed
[-] 127.0.0.1:3233 - TCP closed
[-] 127.0.0.1:3257 - TCP closed
[-] 127.0.0.1:3259 - TCP closed
[-] 127.0.0.1:3276 - TCP closed
[-] 127.0.0.1:3210 - TCP closed
[-] 127.0.0.1:3211 - TCP closed
[-] 127.0.0.1:3248 - TCP closed
[-] 127.0.0.1:3279 - TCP closed
[-] 127.0.0.1:3288 - TCP closed
[-] 127.0.0.1:3246 - TCP closed
[-] 127.0.0.1:3252 - TCP closed
[-] 127.0.0.1:3219 - TCP closed
[-] 127.0.0.1:3251 - TCP closed
[-] 127.0.0.1:3256 - TCP closed
[-] 127.0.0.1:3247 - TCP closed
[-] 127.0.0.1:3296 - TCP closed
[-] 127.0.0.1:3253 - TCP closed
[-] 127.0.0.1:3261 - TCP closed
[-] 127.0.0.1:3231 - TCP closed
[-] 127.0.0.1:3245 - TCP closed
[-] 127.0.0.1:3295 - TCP closed
[-] 127.0.0.1:3254 - TCP closed
[-] 127.0.0.1:3241 - TCP closed
[+] 127.0.0.1:3242 - TCP OPEN
[-] 127.0.0.1:3262 - TCP closed
[-] 127.0.0.1:3265 - TCP closed
[*] Scanned 1 of 1 hosts (100% complete)
[*] Auxiliary module execution completed

```