t5300-pack-object: do not compare binary data using test_cmp

Users may set test_cmp to a comparison tool of their liking. The intent is
that the tool performs comparison of line-oriented texts. However, t5300
uses it also to compare binary data. Change those tests to use 'cmp'.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t5300-pack-object.sh

@@ -151,7 +151,7 @@ test_expect_success \
 	    git cat-file $t $object || return 1
 	 done <obj-list
     } >current &&
-    test_cmp expect current'
+    cmp expect current'
 
 test_expect_success \
     'use packed deltified (REF_DELTA) objects' \
@@ -166,7 +166,7 @@ test_expect_success \
 	    git cat-file $t $object || return 1
 	 done <obj-list
     } >current &&
-    test_cmp expect current'
+    cmp expect current'
 
 test_expect_success \
     'use packed deltified (OFS_DELTA) objects' \
@@ -181,7 +181,7 @@ test_expect_success \
 	    git cat-file $t $object || return 1
 	 done <obj-list
     } >current &&
-    test_cmp expect current'
+    cmp expect current'
 
 unset GIT_OBJECT_DIRECTORY
 
@@ -195,9 +195,9 @@ test_expect_success 'survive missing objects/pack directory' '
 		rm -fr $GOP &&
 		git index-pack --stdin --keep=test <../test-3-${packname_3}.pack &&
 		test -f $GOP/pack-${packname_3}.pack &&
-		test_cmp $GOP/pack-${packname_3}.pack ../test-3-${packname_3}.pack &&
+		cmp $GOP/pack-${packname_3}.pack ../test-3-${packname_3}.pack &&
 		test -f $GOP/pack-${packname_3}.idx &&
-		test_cmp $GOP/pack-${packname_3}.idx ../test-3-${packname_3}.idx &&
+		cmp $GOP/pack-${packname_3}.idx ../test-3-${packname_3}.idx &&
 		test -f $GOP/pack-${packname_3}.keep
 	)
 '