perf build: Fix ccache usage in $(CC) when generating arch errno table

perf build: Fix ccache usage in $(CC) when generating arch errno table

This was introduced by commit e4ffd066ff440a57 ("perf: Normalize gcc
parameter when generating arch errno table").

Assuming the first word of $(CC) is the actual compiler breaks usage
like CC="ccache gcc": the script ends up calling ccache directly with
gcc arguments, what fails. Instead of getting the first word, just
remove from $(CC) any word that starts with a "-". This maintains the
spirit of the original patch, while not breaking ccache users.

Fixes: e4ffd066ff440a57 ("perf: Normalize gcc parameter when generating arch errno table")
Signed-off-by: Antonio Terceiro <antonio.terceiro@linaro.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: He Zhe <zhe.he@windriver.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: http://lore.kernel.org/lkml/20210224130046.346977-1-antonio.terceiro@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>