5526 One more gcc warning for cmd/power

@@ -17,10 +17,11 @@
  * information: Portions Copyright [yyyy] [name of copyright owner]
  *
  * CDDL HEADER END
  */
 /*
+ * Copyright 2015 Gary Mills
  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 
 #include "pmconfig.h"

@@ -1013,11 +1014,11 @@
         if (strncmp(arg, "/dev/zvol/dsk/", 14)) {
                 return (0);
         }
         arg += 14;
         (void) strncpy(pool_name, arg, MAXPATHLEN);
-        if (p = strchr(pool_name, '/'))
+        if ((p = strchr(pool_name, '/')) != NULL)
                 *p = '\0';
         STRCPYLIM(new_cc.cf_fs, p + 1, "statefile path");
 
         if ((lzfs = libzfs_init()) == NULL) {
                 mesg(MERR, "failed to initialize ZFS library\n");