properly count configuration settings in $OCF_RESKEY_CONFIG

- instead of invoking external utilities like `wc', use builtin grep
  `-c' option (specifed by POSIX), which hides regular output and emits
  number of matching lines

Closes-bug: #1349501
Change-Id: I6afaeb0a4945cd7e221a9cf8f47dfa2328015f10
Merge "properly count configuration settings in $OCF_RESKEY_CONFIG"