autorevision: use sed word delimiters for better precision

Fixes wrongly replaced 'cat' in help text:

$ autorevision -h
usage: autorevision {-t output-type | -s symbol} [-o cache-file [-f] ] [-e name] [-U] [-V]
	Options include:
	-t output-type		= specify output type
	-s symbol		= specify symbol output
	-o cache-file		= specify cache file lo/nix/store/1rzzq2wdn5vfgbp5y9613jpdkf8i9ag6-coreutils-8.26/bin/cation
...

(Also replace all occurences per line, in case that should occur.)

pkgs/tools/misc/autorevision/default.nix

@@ -18,11 +18,11 @@ stdenv.mkDerivation rec {
   installFlags = [ "prefix=$(out)" ];
 
   postInstall = ''
-    sed -e "s|cmp|${diffutils}/bin/cmp|" \
-        -e "s|cat|${coreutils}/bin/cat|" \
-        -e "s|grep|${gnugrep}/bin/grep|" \
-        -e "s|\<sed\>|${gnused}/bin/sed|" \
-        -e "s|\<tee\>|${coreutils}/bin/tee|" \
+    sed -e "s|\<cmp\>|${diffutils}/bin/cmp|g" \
+        -e "s|\<cat\>|${coreutils}/bin/cat|g" \
+        -e "s|\<grep\>|${gnugrep}/bin/grep|g" \
+        -e "s|\<sed\>|${gnused}/bin/sed|g" \
+        -e "s|\<tee\>|${coreutils}/bin/tee|g" \
         -i "$out/bin/autorevision"
   '';