iommu/vt-d: Mark functions as static in dmar.c

Mark the functions check_zero_address() and dmar_get_fault_reason() as
static in dmar.c because they are not used outside this file.

This eliminates the following warnings in dmar.c:
drivers/iommu/dmar.c:491:12: warning: no previous prototype for ‘check_zero_address’ [-Wmissing-prototypes]
drivers/iommu/dmar.c:1116:13: warning: no previous prototype for ‘dmar_get_fault_reason’ [-Wmissing-prototypes]
Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Joerg Roedel <joro@8bytes.org>

drivers/iommu/dmar.c

@@ -488,7 +488,7 @@ static void warn_invalid_dmar(u64 addr, const char *message)
 		dmi_get_system_info(DMI_PRODUCT_VERSION));
 }
 
-int __init check_zero_address(void)
+static int __init check_zero_address(void)
 {
 	struct acpi_table_dmar *dmar;
 	struct acpi_dmar_header *entry_header;
@@ -1113,7 +1113,7 @@ static const char *irq_remap_fault_reasons[] =
 
 #define MAX_FAULT_REASON_IDX 	(ARRAY_SIZE(fault_reason_strings) - 1)
 
-const char *dmar_get_fault_reason(u8 fault_reason, int *fault_type)
+static const char *dmar_get_fault_reason(u8 fault_reason, int *fault_type)
 {
 	if (fault_reason >= 0x20 && (fault_reason - 0x20 <
 					ARRAY_SIZE(irq_remap_fault_reasons))) {