scripts/faddr2line: Add CONFIG_DEBUG_INFO check

Otherwise without DWARF it spits out gibberish and gives no indication
of what the problem is.
Suggested-by: John Garry <john.garry@huawei.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: John Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/ffa7734c929445caa374bf9e68078300174f09b4.1658426357.git.jpoimboe@kernel.org

scripts/faddr2line

@@ -61,6 +61,7 @@ die() {
 READELF="${CROSS_COMPILE:-}readelf"
 ADDR2LINE="${CROSS_COMPILE:-}addr2line"
 AWK="awk"
+GREP="grep"
 
 command -v ${AWK} >/dev/null 2>&1 || die "${AWK} isn't installed"
 command -v ${READELF} >/dev/null 2>&1 || die "${READELF} isn't installed"
@@ -271,6 +272,8 @@ LIST=0
 [[ ! -f $objfile ]] && die "can't find objfile $objfile"
 shift
 
+${READELF} --section-headers --wide $objfile | ${GREP} -q '\.debug_info' || die "CONFIG_DEBUG_INFO not enabled"
+
 DIR_PREFIX=supercalifragilisticexpialidocious
 find_dir_prefix $objfile