binfmt.sh: use read in raw mode

The read builtin in most shells will interpret backslash characters
as escapes, and they are lost when reading binfmt files line-by-line.
This causes magic strings containing backslashes to be mangled and
become invalid, resulting in erroneous 'invalid entry' messages.

The -r option to read disables special handling of backslashes and
keeps all lines intact.

X-Gentoo-Bug: 575114
X-Gentoo-Bug-URL: https://bugs.gentoo.org/show_bug.cgi?id=575114

sh/binfmt.sh.in

@@ -22,7 +22,7 @@ apply_file() {
 
 	### FILE FORMAT ###
 	# See https://www.kernel.org/doc/Documentation/binfmt_misc.txt
-	while read line; do
+	while read -r line; do
 		LINENUM=$(( LINENUM+1 ))
 		case $line in
 			\#*) continue ;;