drivers/misc/sgi-gru/grufault.c: fix a sanity test in gru_set_context_option()

"req.val1 == -1" is valid but it doesn't make sense to check gru_base[-1].
 gru_base[] is a global array.
Signed-off-by: NDimitri Sivanich <sivanich@sgi.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Robin Holt <holt@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/misc/sgi-gru/grufault.c

@@ -876,8 +876,9 @@ int gru_set_context_option(unsigned long arg)
 	switch (req.op) {
 	case sco_blade_chiplet:
 		/* Select blade/chiplet for GRU context */
-		if (req.val1 < -1 || req.val1 >= GRU_MAX_BLADES || !gru_base[req.val1] ||
-		    req.val0 < -1 || req.val0 >= GRU_CHIPLETS_PER_HUB) {
+		if (req.val0 < -1 || req.val0 >= GRU_CHIPLETS_PER_HUB ||
+		    req.val1 < -1 || req.val1 >= GRU_MAX_BLADES ||
+		    (req.val1 >= 0 && !gru_base[req.val1])) {
 			ret = -EINVAL;
 		} else {
 			gts->ts_user_blade_id = req.val1;