mesh: Fix the wrong way to detect the trailing space. Assignment n bytes to link.rx.buf->om_len will lead to n bytes decrease of OS_MBUF_TRAILINGSPACE(link.rx.buf), so we should get the OS_MBUF_TRAILINGSPACE(link.rx.buf) before assignment net_buf_simple_pull_be16(buf) to link.rx.buf->om_len.
mesh: Fix the wrong way to detect the trailing space.
Assignment n bytes to link.rx.buf->om_len will lead to
n bytes decrease of OS_MBUF_TRAILINGSPACE(link.rx.buf),
so we should get the OS_MBUF_TRAILINGSPACE(link.rx.buf)
before assignment net_buf_simple_pull_be16(buf) to
link.rx.buf->om_len.

apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble