bbclass: bb.fatal() clean up

The bb.fatal() is defined as:

def fatal(*args):
    logger.critical(''.join(args))
    sys.exit(1)

So anything after bb.fatal() in the same code block doesn't have any
effect, e.g.:

    bb.fatal("%s_%s: %s" % (var, pkg, e))
    raise e

The "raise e" should be removed.

I searched all the files which use bb.fatal(), only the following 3
classes have this issues:

  insane.bbclass
  package.bbclass
  package_rpm.bbclass

[YOCTO #4461]

(From OE-Core rev: 4c47525c5a171b1282615c9fbc7d84addef85f92)

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/package_rpm.bbclass

@@ -672,12 +672,10 @@ python write_specfile () {
     pkgdest = d.getVar('PKGDEST', True)
     if not pkgdest:
         bb.fatal("No PKGDEST")
-        return
 
     outspecfile = d.getVar('OUTSPECFILE', True)
     if not outspecfile:
         bb.fatal("No OUTSPECFILE")
-        return
 
     # Construct the SPEC file...
     srcname    = strip_multilib(d.getVar('PN', True), d)