time: ntp: clean up second_overflow()

Impact: cleanup, no functionality changed

The 'time_adj' local variable is named in a very confusing
way because it almost shadows the 'time_adjust' global
variable - which is used in this same function.

Rename it to 'delta' - to make them stand apart more clearly.

kernel/time/ntp.o:

   text	   data	    bss	    dec	    hex	filename
   2545	    114	    144	   2803	    af3	ntp.o.before
   2545	    114	    144	   2803	    af3	ntp.o.after

md5:
   1bf0b3be564512279ba7cee299d1d2be  ntp.o.before.asm
   1bf0b3be564512279ba7cee299d1d2be  ntp.o.after.asm
Signed-off-by: Ingo Molnar <mingo@elte.hu>

kernel/time/ntp.c

@@ -236,7 +236,7 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
  */
 void second_overflow(void)
 {
-	s64 time_adj;
+	s64 delta;
 
 	/* Bump the maxerror field */
 	time_maxerror += MAXFREQ / NSEC_PER_USEC;
@@ -250,9 +250,10 @@ void second_overflow(void)
 	 * reduced by a fixed factor times the time constant.
 	 */
 	tick_length	 = tick_length_base;
-	time_adj	= shift_right(time_offset, SHIFT_PLL + time_constant);
-	time_offset	-= time_adj;
-	tick_length	+= time_adj;
+
+	delta		 = shift_right(time_offset, SHIFT_PLL + time_constant);
+	time_offset	-= delta;
+	tick_length	+= delta;
 
 	if (!time_adjust)
 		return;