ACPI / OSL: Mark the function acpi_table_checksum() as static

Marks the function acpi_table_checksum() as static in osl.c
because it is not used outside this file.

This eliminates the following warning in osl.c:
drivers/acpi/osl.c:547:11: warning: no previous prototype for
‘acpi_table_checksum’ [-Wmissing-prototypes]

Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index 26c1113..7865a80 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -540,7 +540,7 @@
 static int all_tables_size;
 
 /* Copied from acpica/tbutils.c:acpi_tb_checksum() */
-u8 __init acpi_table_checksum(u8 *buffer, u32 length)
+static u8 __init acpi_table_checksum(u8 *buffer, u32 length)
 {
 	u8 sum = 0;
 	u8 *end = buffer + length;