[PATCH 5.4 458/475] tools build: Use $(shell ) instead of `` to get embedded libperls ccopts

[Greg Kroah-Hartman]

From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>

commit 541f695cbcb6932c22638b06e0cbe1d56177e2e9 upstream.

Just like its done for ldopts and for both in tools/perf/Makefile.config.

Using `` to initialize PERL_EMBED_CCOPTS somehow precludes using:

  $(filter-out SOMETHING_TO_FILTER,$(PERL_EMBED_CCOPTS))

And we need to do it to allow for building with versions of clang where
some gcc options selected by distros are not available.

Tested-by: Sedat Dilek <sedat.dilek@xxxxxxxxx> # Debian/Selfmade LLVM-14 (x86-64)
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Fangrui Song <maskray@xxxxxxxxxx>
Cc: Florian Fainelli <f.fainelli@xxxxxxxxx>
Cc: Ian Rogers <irogers@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: John Keeping <john@xxxxxxxxxxxx>
Cc: Leo Yan <leo.yan@xxxxxxxxxx>
Cc: Michael Petlan <mpetlan@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Nathan Chancellor <nathan@xxxxxxxxxx>
Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Link: http://lore.kernel.org/lkml/YktYX2OnLtyobRYD@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 tools/build/feature/Makefile |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/tools/build/feature/Makefile
+++ b/tools/build/feature/Makefile
@@ -204,7 +204,7 @@ strip-libs = $(filter-out -l%,$(1))
 PERL_EMBED_LDOPTS = $(shell perl -MExtUtils::Embed -e ldopts 2>/dev/null)
 PERL_EMBED_LDFLAGS = $(call strip-libs,$(PERL_EMBED_LDOPTS))
 PERL_EMBED_LIBADD = $(call grep-libs,$(PERL_EMBED_LDOPTS))
-PERL_EMBED_CCOPTS = `perl -MExtUtils::Embed -e ccopts 2>/dev/null`
+PERL_EMBED_CCOPTS = $(shell perl -MExtUtils::Embed -e ccopts 2>/dev/null)
 FLAGS_PERL_EMBED=$(PERL_EMBED_CCOPTS) $(PERL_EMBED_LDOPTS)
 
 ifeq ($(CC_NO_CLANG), 0)