x86/resctrl: Remove redundant assignment to variable chunks

The variable chunks is being shifted right and re-assinged the shifted
value which is then returned. Since chunks is not being read afterwards
the assignment is redundant and the >>= operator can be replaced with a
shift >> operator instead.
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Link: https://lkml.kernel.org/r/20211207223735.35173-1-colin.i.king@gmail.com

arch/x86/kernel/cpu/resctrl/monitor.c

@@ -282,7 +282,7 @@ static u64 mbm_overflow_count(u64 prev_msr, u64 cur_msr, unsigned int width)
 	u64 shift = 64 - width, chunks;
 
 	chunks = (cur_msr << shift) - (prev_msr << shift);
-	return chunks >>= shift;
+	return chunks >> shift;
 }
 
 static u64 __mon_event_count(u32 rmid, struct rmid_read *rr)