package.bbclass: Fix per-file dependency generation

package.bbclass: Fix per-file dependency generation

The overall file list was being constructed with the wrong variable, it
should have had FLIST in the name.

Also it was possible to construct the system with some illegal variable
names.  Names that would have include "[]".  So translate these away...

Finally fix an issues where a filename with an _ could cause a package
variable conflict.  Again translate this away..

Signed-off-by: Mark Hatle <mhatle@windriver.com>