functions.sh: do not hard code path in e* wrapper functions

We should use the "command" shell builtin to execute a binary from
within the wrapper with the same name. Hard coding the path to the
binary makes our test suite fail.

sh/functions.sh.in

@@ -105,7 +105,7 @@ else
 	# the last ecmd
 	for _e in ebegin eend error errorn einfo einfon ewarn ewarnn ewend \
 		vebegin veend veinfo vewarn vewend; do
-		eval "$_e() { local _r; @LIBEXECDIR@/bin/$_e \"\$@\"; _r=\$?; \
+		eval "$_e() { local _r; command $_e \"\$@\"; _r=\$?; \
 		export EINFO_LASTCMD=$_e; return \$_r; }"
 	done
 	unset _e