patches: Optimize processing of unapplied patches

* Don't check for $strip = ab twice, once is enough.
* Quote the file names to be suitable in regular expressions only
  once, instead of doing it again for every patch. This fixes a
  performance regression introduced in 8ebb056d ("patches: Add
  support for multiple files"), sorry about that.

These two simple changes bring a huge performance boost on unapplied
patches, of about 50% in the single file case and growing as you add
files.

0 files changed, 0 insertions, 0 deletions