miniflow: Remove unused value_inline branch from miniflow_move()

The branch is unused as size < sizeof dst->inline_values must
always be true for inlined values. Hitting the branch would lead
to corruption as inline_values is accessed out of bounds.

Remove branch and and add assertion.

Cc: Jarno Rajahalme <jrajahalme@nicira.com>
Signed-off-by: Thomas Graf <tgraf@noironetworks.com>
miniflow: Always destroy src in miniflow_move()

According to the function comment, src is always destroyed.

Cc: Jarno Rajahalme <jrajahalme@nicira.com>
Signed-off-by: Thomas Graf <tgraf@noironetworks.com>