Backport: Update tests to be endian safe, fix FTBFS on s390x

Also, use %autopatch to apply the patches.

python-pip.spec

@@ -90,6 +90,12 @@ Patch4:         dummy-certifi.patch
 # this warning is juts moot. Also, the warning breaks CPython test suite.
 Patch5:         nowarn-pip._internal.main.patch
 
+# Backport: Update tests to be endian safe
+# This updates `test_path_to_display` and `test_str_to_display__encoding`
+# to use the endian safe expected result instead of the hardcoded one.
+# This fixes https://github.com/pypa/pip/issues/7921
+Patch6:         https://github.com/pypa/pip/commit/b30dd1e04e.patch
+
 # Downstream only patch
 # Users might have local installations of pip from using
 # `pip install --user --upgrade pip` on older/newer versions.
@@ -253,11 +259,7 @@ mv python-docs-theme-2018.2 python-docs-theme
 popd
 %endif
 
-%patch1 -p1
-%patch2 -p1
-%patch3 -p1
-%patch4 -p1
-%patch5 -p1
+%autopatch -p1
 
 # this goes together with patch4
 rm src/pip/_vendor/certifi/*.pem