veyron/lib/glob: Fix bad pattern detection

filepath.Match() never returns an error when matching against an empty
name.

This caused mounttabled to panic when it received an invalid pattern.

panic: Error in glob pattern found.
[...]
veyron.io/veyron/veyron/lib/glob.(*Glob).MatchInitialSegment(0xc20df9c920,
0xc20f1395ed, 0xd, 0xc20df9c960, 0x2)
        /home/ashankar/veyron/veyron/go/src/veyron.io/veyron/veyron/lib/glob/glob.go:91 +0x152

Change-Id: Id6a184a3838643350555bbf9afed5133a216033c
2 files changed
tree: a95333cb8157a7340de3a60c51c079b4c2242cd8
  1. lib/
  2. profiles/
  3. runtimes/
  4. security/
  5. services/
  6. tools/