acpi/acpi.c: Return function argument when bailing out

Returning a constant value makes the function easier to read and think
about.

Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Change-Id: Ifdf7acec38a7c958aac2cf1f3bbf16c27fa90b8c
Reviewed-on: https://review.coreboot.org/c/coreboot/+/75903
Reviewed-by: Lean Sheng Tan <sheng.tan@9elements.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/acpi/acpi.c b/src/acpi/acpi.c
index ce14538..cfc388b 100644
--- a/src/acpi/acpi.c
+++ b/src/acpi/acpi.c
@@ -1931,7 +1931,7 @@
 	dsdt_file = cbfs_map(CONFIG_CBFS_PREFIX "/dsdt.aml", &dsdt_size);
 	if (!dsdt_file) {
 		printk(BIOS_ERR, "No DSDT file, skipping ACPI tables\n");
-		return current;
+		return start;
 	}
 
 	if (dsdt_file->length > dsdt_size
@@ -1939,7 +1939,7 @@
 	    || memcmp(dsdt_file->signature, "DSDT", 4) != 0) {
 		printk(BIOS_ERR, "Invalid DSDT file, skipping ACPI tables\n");
 		cbfs_unmap(dsdt_file);
-		return current;
+		return start;
 	}
 
 	slic_file = cbfs_map(CONFIG_CBFS_PREFIX "/slic", &slic_size);