net: caif: fix misleading indentation

gcc points out code that is not indented the way it is
interpreted:

net/caif/cfpkt_skbuff.c: In function 'cfpkt_setlen':
net/caif/cfpkt_skbuff.c:289:4: error: statement is indented as if it were guarded by... [-Werror=misleading-indentation]
    return cfpkt_getlen(pkt);
    ^~~~~~
net/caif/cfpkt_skbuff.c:286:3: note: ...this 'else' clause, but it is not
   else
   ^~~~

It is clear from the context that not returning here would be
a bug, as we'd end up passing a negative length into a function
that takes a u16 length, so it is not missing curly braces
here, and I'm assuming that the indentation is the only part
that's wrong about it.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>