powerpc/oprofile: Fix error in oprofile power7_marked_instr_event() function

The calculation for the left shift of the mask OPROFILE_PM_PMCSEL_MSK has an
error.  The calculation is should be to shift left by (max_cntrs - cntr) times
the width of the pmsel field width.  However, the #define OPROFILE_MAX_PMC_NUM
was used instead of OPROFILE_PMSEL_FIELD_WIDTH.  This patch fixes the
calculation.
Signed-off-by: Carl Love <cel@us.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/oprofile/op_model_power4.c

@@ -52,7 +52,7 @@ static int power7_marked_instr_event(u64 mmcr1)
 	for (pmc = 0; pmc < 4; pmc++) {
 		psel = mmcr1 & (OPROFILE_PM_PMCSEL_MSK
 				<< (OPROFILE_MAX_PMC_NUM - pmc)
-				* OPROFILE_MAX_PMC_NUM);
+				* OPROFILE_PMSEL_FIELD_WIDTH);
 		psel = (psel >> ((OPROFILE_MAX_PMC_NUM - pmc)
 				 * OPROFILE_PMSEL_FIELD_WIDTH)) & ~1ULL;
 		unit = mmcr1 & (OPROFILE_PM_UNIT_MSK