staging: sm750fb: replace absDiff with kernel standard abs macro

<linux/kernel.h> already has 'abs', use it instead of custom absDiff
Signed-off-by: Mike Rapoport <mike.rapoport@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/sm750fb/ddk750_chip.c

+#include <linux/kernel.h>
 #include <linux/sizes.h>
 
 #include "ddk750_help.h"
@@ -335,7 +336,7 @@ unsigned int calcPllValue(unsigned int request_orig, pll_value_t *pll)
 				unsigned int diff;
 
 				tmpClock = pll->inputFreq * M / N / X;
-				diff = absDiff(tmpClock, request_orig);
+				diff = abs(tmpClock - request_orig);
 				if (diff < mini_diff) {
 					pll->M = M;
 					pll->N = N;

drivers/staging/sm750fb/sm750_help.h

@@ -38,14 +38,6 @@
 #define FIELD_SIZE(field)               (1 + FIELD_END(field) - FIELD_START(field))
 #define FIELD_MASK(field)               (((1 << (FIELD_SIZE(field)-1)) | ((1 << (FIELD_SIZE(field)-1)) - 1)) << FIELD_START(field))
 
-static inline unsigned int absDiff(unsigned int a, unsigned int b)
-{
-	if (a < b)
-		return b-a;
-	else
-		return a-b;
-}
-
 /* n / d + 1 / 2 = (2n + d) / 2d */
 #define roundedDiv(num, denom)	((2 * (num) + (denom)) / (2 * (denom)))
 #define MHz(x) ((x) * 1000000)