scripts/bitbake: Remove all instances of paths to a layer's scripts directory.

scripts/bitbake: Remove all instances of paths to a layer's scripts directory.

* Currently the assumption is made that only oe-core can include a scripts
  directory.

* However, when other layers create a scripts directory the bitbake script
  freaks out causing a infinite recursive loop until it crashes.

* Simply changing the regular expression to remove all instances of scripts path
  instead of just the first one fixes this problem.

 [Yocto Bug 3872]

Signed-off-by: Franklin S. Cooper Jr <fcooper@ti.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>