gfs2: Minor gfs2_glock_cb cleanup

In gfs2_glock_cb(), we only need to calculate the glock hold time for
inode glocks; the value is unused otherwise.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

fs/gfs2/glock.c

@@ -1885,14 +1885,16 @@ void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs)
 void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state)
 {
 	unsigned long delay = 0;
-	unsigned long holdtime;
-	unsigned long now = jiffies;
 
 	gfs2_glock_hold(gl);
 	spin_lock(&gl->gl_lockref.lock);
-	holdtime = gl->gl_tchange + gl->gl_hold_time;
 	if (!list_empty(&gl->gl_holders) &&
 	    gl->gl_name.ln_type == LM_TYPE_INODE) {
+		unsigned long now = jiffies;
+		unsigned long holdtime;
+
+		holdtime = gl->gl_tchange + gl->gl_hold_time;
+
 		if (time_before(now, holdtime))
 			delay = holdtime - now;
 		if (test_bit(GLF_HAVE_REPLY, &gl->gl_flags))