MFC r278297:

MFC r278297:

Fix two clang 3.6.0 warnings in usr.sbin/syslogd:

usr.sbin/syslogd/syslogd.c:1023:10: error: address of array 'f->f_prevline' will always evaluate to 'true' [-Werror,-Wpointer-bool-conversion]
		    f->f_prevline && !strcmp(msg, f->f_prevline) &&
		    ~~~^~~~~~~~~~
usr.sbin/syslogd/syslogd.c:1178:16: error: address of array 'f->f_prevline' will always evaluate to 'true' [-Werror,-Wpointer-bool-conversion]
	} else if (f->f_prevline) {
	       ~~  ~~~^~~~~~~~~~

In both cases, the f_prevline field of struct filed is a char array, so
it can never be null.  Remove the checks.

Reviewed by:	jilles
Differential Revision: https://reviews.freebsd.org/D1716

git-svn-id: svn://svn.freebsd.org/base/stable/10@278437 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f