fix regexp match against `file /proc/$$/exe` for -fPIE bash
Now that bash is built with PIE enabled, keyutils' check for endianness
fails because file no longer returns "executable", but instead returns
"shared object" for file << 5.33 and "pie executable" for file >= 5.33.

--- a/tests/toolbox.inc.sh
+++ b/tests/toolbox.inc.sh
@@ -13,10 +13,10 @@
 echo === $OUTPUTFILE ===
 
 endian=`file -L /proc/$$/exe`
-if expr "$endian" : '.* MSB \+\(executable\|shared object).*' >&/dev/null
+if expr "$endian" : '.* MSB \+\(executable\|shared object\|pie executable\).*' >&/dev/null
 then
     endian=BE
-elif expr "$endian" : '.* LSB \+\(executable\|shared object\).*' >&/dev/null
+elif expr "$endian" : '.* LSB \+\(executable\|shared object\|pie executable\).*' >&/dev/null
 then
     endian=LE
 else