Linux 4.19.50

Merge 49 patches from 4.19.50 stable
branch (53 total) beside 4 already merged patches:
893e2a5 neighbor: Call __ipv4_neigh_lookup_noref in neigh_xmit
c63ce71 pstore: Remove needless lock during console writes
ec8a9eb TTY: serial_core, add ->install
645fa68 ipv4: Define __ipv4_neigh_lookup_noref when CONFIG_INET is disabled
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

Makefile

 # SPDX-License-Identifier: GPL-2.0
 VERSION = 4
 PATCHLEVEL = 19
-SUBLEVEL = 49
+SUBLEVEL = 50
 EXTRAVERSION =
 NAME = "People's Front"