[XS] Change in coreboot[main]: Fix no-op for empty argument in Makefile for Bash compatibility

[Balaji Manigandan (Code Review)]

Balaji Manigandan has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/83887?usp=email )

Change subject: Fix no-op for empty argument in Makefile for Bash compatibility
......................................................................

Fix no-op for empty argument in Makefile for Bash compatibility

This change addresses an issue encountered in Ubuntu 24.04 with GNU Bash
version 5.2.21, where the Makefile would fail with the error:

/bin/bash: -c: option requires an argument
    make: *** [Makefile.mk:1440: build/coreboot.pre] Error 2

The error was triggered by an empty third argument `$(3)` in a conditional
`$(if ...)` statement. The original line did not specify an explicit no-op
for the case when `$(3)` is empty, which led to the execution of an incomplete
command.

By adding a colon `:` as a no-op command in the else-part of the `$(if ...)`,
we ensure that a harmless command is executed when `$(3)` is empty, preventing
the Makefile from failing due to a missing argument.

This fix ensures compatibility with the newer Bash version and prevents the
Makefile from breaking under the specified conditions.

Change-Id: I276e89792779832edf325d4f781aa8df101e9091
Signed-off-by: Manigandan, Balaji 
---
M Makefile.mk
1 file changed, 1 insertion(+), 1 deletion(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/87/83887/1

diff --git a/Makefile.mk b/Makefile.mk
index 901d6b2..0853c66 100644
--- a/Makefile.mk
+++ b/Makefile.mk
@@ -992,7 +992,7 @@
 #          non-empty if file removal requested)
 define cbfs-add-cmd
    printf "    CBFS       $(call extract_nth,2,$(1))\n"
-	$(if $(3),-$(CBFSTOOL) $@.tmp remove -n $(call extract_nth,2,$(file)) 2>/dev/null)
+	$(if $(3),-$(CBFSTOOL) $@.tmp remove -n $(call extract_nth,2,$(file)) 2>/dev/null,:)
    $(call cbfs-add-cmd-for-region,$(1),$(2))
 endef