Review 25239

C. Thomas Tyler
Replaced references to /tmp with P4TMP (e.g. /p4/N/tmp) to avoid
issues with SELinux incompatibility.

For p4verify.sh, enhanced:
* Minor performance enhancement: Added '-m1' flag to egrep that
  determines whether to exit code with non-zero, as we only need
  to detect one occurence.
* Changed 'Warning:' to 'Error:' if verify errors are detected.
* Removed redundant check that SDP_INSTANCE is set.
* Added total time info.
* Adjusted to pass 'shellcheck.sh' check.
Tip: Use n and p to cycle through the changes.