perf beauty mmap_flags: Check if the arch has a mmap.h file

If not, then just use what is in asm-generic. This fixes the build for
my sh4, m68k and riscv64 perf test build containers that were failing
due to 80ee5668b8a7 ("perf beauty: Add a generator for MAP_ mmap's flag
constants"), that were not covered in the cset introducing those
tools/arch/*/include/uapi/asm/mman.h files.

f3539c12d819 ("tools include: Add uapi mman.h for each architecture")

Cc: Adrian Hunter <[e-mail]>
Cc: David Ahern <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Wang Nan <[e-mail]>
Fixes: 80ee5668b8a7 ("perf beauty: Add a generator for MAP_ mmap's flag constants")
Link: https://lkml.kernel.org/n/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/Makefile.perf

···
 mmap_flags_array := $(beauty_outdir)/mmap_flags_array.c
 mmap_flags_tbl := $(srctree)/tools/perf/trace/beauty/mmap_flags.sh
 
-$(mmap_flags_array): $(asm_generic_uapi_dir)/mman.h $(asm_generic_uapi_dir)/mman-common.h $(arch_asm_uapi_dir)/mman.h $(mmap_flags_tbl)
+$(mmap_flags_array): $(asm_generic_uapi_dir)/mman.h $(asm_generic_uapi_dir)/mman-common.h $(mmap_flags_tbl)
 	$(Q)$(SHELL) '$(mmap_flags_tbl)' $(asm_generic_uapi_dir) $(arch_asm_uapi_dir) > $@
 
 mount_flags_array := $(beauty_outdir)/mount_flags_array.c

tools/perf/trace/beauty/mmap_flags.sh

···
 (egrep $regex ${arch_mman} | \
 	sed -r "s/$regex/\2 \1/g"	| \
 	xargs printf "\t[ilog2(%s) + 1] = \"%s\",\n")
-egrep -q '#[[:space:]]*include[[:space:]]+<uapi/asm-generic/mman.*' ${arch_mman} &&
+[ ! -f ${arch_mman} || egrep -q '#[[:space:]]*include[[:space:]]+<uapi/asm-generic/mman.*' ${arch_mman} ] &&
 (egrep $regex ${header_dir}/mman-common.h | \
 	egrep -vw 'MAP_(UNINITIALIZED|TYPE|SHARED_VALIDATE)' | \
 	sed -r "s/$regex/\2 \1/g"	| \
 	xargs printf "\t[ilog2(%s) + 1] = \"%s\",\n")
-egrep -q '#[[:space:]]*include[[:space:]]+<uapi/asm-generic/mman.h>.*' ${arch_mman} &&
+[ ! -f ${arch_mman} || egrep -q '#[[:space:]]*include[[:space:]]+<uapi/asm-generic/mman.h>.*' ${arch_mman} ] &&
 (egrep $regex ${header_dir}/mman.h | \
 	sed -r "s/$regex/\2 \1/g"	| \
 	xargs printf "\t[ilog2(%s) + 1] = \"%s\",\n")