lib/bb/fetch2: ignore remote URIs when doing file checksums

lib/bb/fetch2: ignore remote URIs when doing file checksums

Skip evaluating remote URIs when doing local file checksums, because we
don't need to process them and doing so will trigger a parse failure if
SRCREV is not fully specified. Whilst this is just delaying a check
until runtime (when do_fetch runs for the recipe) we're only validating
this here accidentally and if we did wish to check it during parsing it
ought to be done explicitly.

Fixes [YOCTO #2512]

(Bitbake rev: 99feb77c2de707f2d825566cf48371c48f450e3e)

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>