datatype: revert "fix crash if wrong integer type is passed"

datatype: revert "fix crash if wrong integer type is passed"

Revert commit a320531e7:

We have generic type checks that handle this case just fine and indeed
the bugzilla entry mentioned in the reverted patch states:

BUG: invalid input descriptor type 538976288
nft: src/erec.c:100: erec_print: Assertion `0' failed.
Abandon

So the problem is not related to datatypes at all and generic type
checking works perfectly fine:

<cmdline>:1:52-57: Error: datatype mismatch, expected Ethernet protocol, expression has type Internet protocol
add rule ip6 filter input position 4 meta protocol icmpv6 accept
                                     ~~~~~~~~~~~~~ ^^^^^^

Signed-off-by: Patrick McHardy <kaber@trash.net>