ARM: use a temporary variable to hold maximum vmalloc size

We calculate the maximum size of the vmalloc space twice in
early_vmalloc(). Use a temporary variable to hold this value.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Yanfei Xu <yanfei.xu@windriver.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

arch/arm/mm/mmu.c

@@ -1132,6 +1132,7 @@ static unsigned long __initdata vmalloc_min =
 static int __init early_vmalloc(char *arg)
 {
 	unsigned long vmalloc_reserve = memparse(arg, NULL);
+	unsigned long vmalloc_max;
 
 	if (vmalloc_reserve < SZ_16M) {
 		vmalloc_reserve = SZ_16M;
@@ -1139,8 +1140,9 @@ static int __init early_vmalloc(char *arg)
 			vmalloc_reserve >> 20);
 	}
 
-	if (vmalloc_reserve > VMALLOC_END - (PAGE_OFFSET + SZ_32M)) {
-		vmalloc_reserve = VMALLOC_END - (PAGE_OFFSET + SZ_32M);
+	vmalloc_max = VMALLOC_END - (PAGE_OFFSET + SZ_32M);
+	if (vmalloc_reserve > vmalloc_max) {
+		vmalloc_reserve = vmalloc_max;
 		pr_warn("vmalloc area is too big, limiting to %luMB\n",
 			vmalloc_reserve >> 20);
 	}