x86/mce/threshold: Remove the redundant this_cpu_dec_return()

The 'storm' variable points to this_cpu_ptr(&storm_desc). Access the
'stormy_bank_count' field through the 'storm' to avoid calling
this_cpu_*() on the same per-CPU variable twice.

This minor optimization reduces the text size by 16 bytes.

  $ size threshold.o.*
     text	   data	    bss	    dec	    hex	filename
     1395	   1664	      0	   3059	    bf3	threshold.o.old
     1379	   1664	      0	   3043	    be3	threshold.o.new

No functional changes intended.

Signed-off-by: Qiuxu Zhuo <[email protected]>
Signed-off-by: Borislav Petkov (AMD) <[email protected]>
Reviewed-by: Tony Luck <[email protected]>
Reviewed-by: Nikolay Borisov <[email protected]>
Reviewed-by: Sohil Mehta <[email protected]>
Reviewed-by: Yazen Ghannam <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

Author: qzhuo2

arch/x86/kernel/cpu/mce/threshold.c

@@ -90,7 +90,7 @@ void cmci_storm_end(unsigned int bank)
 	storm->banks[bank].in_storm_mode = false;
 
 	/* If no banks left in storm mode, stop polling. */
-	if (!this_cpu_dec_return(storm_desc.stormy_bank_count))
+	if (!--storm->stormy_bank_count)
 		mce_timer_kick(false);
 }