libc: Remove CONFIG_LIBC_ERR

let linker remove the unused object files from the final image

Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>

libs/libc/misc/Make.defs

@@ -37,7 +37,7 @@ endif
 
 CSRCS += lib_dumpbuffer.c lib_dumpvbuffer.c lib_fnmatch.c lib_debug.c
 CSRCS += lib_crc64.c lib_crc32.c lib_crc16.c lib_crc8.c lib_crc8ccitt.c
-CSRCS += lib_crc8table.c lib_glob.c lib_execinfo.c lib_ftok.c
+CSRCS += lib_crc8table.c lib_glob.c lib_execinfo.c lib_ftok.c lib_err.c
 
 # Keyboard driver encoder/decoder
 
@@ -57,10 +57,6 @@ ifeq ($(CONFIG_LIBC_ENVPATH),y)
 CSRCS += lib_envpath.c
 endif
 
-ifeq ($(CONFIG_LIBC_ERR),y)
-CSRCS += lib_err.c
-endif
-
 # To ensure uname information is newest,
 # add lib_utsname.o to phony target for force rebuild