Fix the following -Werror warning from clang 3.5.0, while building
usr.bin/cpio on amd64 (or any arch with 64-bit time_t):

contrib/libarchive/cpio/cpio.c:1143:6: error: absolute value function 'abs' given an argument of type 'long' but has parameter of type 'int' which may cause truncation of value [-Werror,-Wabsolute-value]
        if (abs(mtime - now) > (365/2)*86400)
            ^
contrib/libarchive/cpio/cpio.c:1143:6: note: use function 'labs' instead
        if (abs(mtime - now) > (365/2)*86400)
            ^~~
            labs
1 error generated.

This is because time_t is a long on amd64. To avoid the warning, just
copy the equivalent test from a few lines before, which is used in the
Windows case, and which is type safe.

Reviewed by:	emaste
MFC after:	3 days
Differential Revision: https://reviews.freebsd.org/D1198
Fix the following -Werror warnings from clang 3.5.0, while building
usr.bin/locate:

usr.bin/locate/locate/util.c:249:29: error: taking the absolute value of unsigned type 'unsigned int' has no effect [-Werror,-Wabsolute-value]
                            MAXPATHLEN, abs(i) < abs(htonl(i)) ? i : htonl(i));
                                                 ^
usr.bin/locate/locate/util.c:249:29: note: remove the call to 'abs' since unsigned values cannot be negative
                            MAXPATHLEN, abs(i) < abs(htonl(i)) ? i : htonl(i));
                                                 ^~~
usr.bin/locate/locate/util.c:274:32: error: taking the absolute value of unsigned type 'unsigned int' has no effect [-Werror,-Wabsolute-value]
                            MAXPATHLEN, abs(word) < abs(htonl(word)) ? word :
                                                    ^
usr.bin/locate/locate/util.c:274:32: note: remove the call to 'abs' since unsigned values cannot be negative
                            MAXPATHLEN, abs(word) < abs(htonl(word)) ? word :
                                                    ^~~

The problem is that ntohl() always returns an unsigned quantity.  In
this case, it's expected to be cast back to a signed integer, but to
stop complaints about abs() we just store it into an integer, and don't
call ntohl() again.

Reviewed by:	ngie
MFC after:	3 days
Differential Revision: https://reviews.freebsd.org/D1196