powerpc/spufs: Remove set but not used variable 'dummy'

Fixes gcc '-Wunused-but-set-variable' warning:
# WARNING: Fixes tag on line 3 doesn't match correct format
# WARNING: Fixes tag on line 3 doesn't match correct format
# WARNING: Fixes tag on line 3 doesn't match correct format
# WARNING: Fixes tag on line 3 doesn't match correct format
# WARNING: Fixes tag on line 3 doesn't match correct format

arch/powerpc/platforms/cell/spufs/switch.c: In function 'check_ppu_mb_stat':
arch/powerpc/platforms/cell/spufs/switch.c:1660:6: warning:
variable ‘dummy’ set but not used [-Wunused-but-set-variable]

arch/powerpc/platforms/cell/spufs/switch.c: In function 'check_ppuint_mb_stat':
arch/powerpc/platforms/cell/spufs/switch.c:1675:6: warning:
variable ‘dummy’ set but not used [-Wunused-but-set-variable]

It never used since introduction.

Signed-off-by: Baokun Li <[e-mail]>
Acked-by: Arnd Bergmann <[e-mail]>
Signed-off-by: Michael Ellerman <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

arch/powerpc/platforms/cell/spufs/switch.c

···
 static inline void check_ppu_mb_stat(struct spu_state *csa, struct spu *spu)
 {
 	struct spu_problem __iomem *prob = spu->problem;
-	u32 dummy = 0;
 
 	/* Restore, Step 66:
 	 *     If CSA.MB_Stat[P]=0 (mailbox empty) then
 	 *     read from the PPU_MB register.
 	 */
 	if ((csa->prob.mb_stat_R & 0xFF) == 0) {
-		dummy = in_be32(&prob->pu_mb_R);
+		in_be32(&prob->pu_mb_R);
 		eieio();
 	}
 }
···
 static inline void check_ppuint_mb_stat(struct spu_state *csa, struct spu *spu)
 {
 	struct spu_priv2 __iomem *priv2 = spu->priv2;
-	u64 dummy = 0UL;
 
 	/* Restore, Step 66:
 	 *     If CSA.MB_Stat[I]=0 (mailbox empty) then
 	 *     read from the PPUINT_MB register.
 	 */
 	if ((csa->prob.mb_stat_R & 0xFF0000) == 0) {
-		dummy = in_be64(&priv2->puint_mb_R);
+		in_be64(&priv2->puint_mb_R);
 		eieio();
 		spu_int_stat_clear(spu, 2, CLASS2_ENABLE_MAILBOX_INTR);
 		eieio();