[ Upstream commit f03560a57c1f60db6ac23ffd9714e1c69e2f95c7 ] When using pthreads, one has to compile and link with -lpthread, otherwise e.g. glibc is not guaranteed to be reentrant. This replaces -lpthread. Reported-by: Matthew Wilcox <willy@infradead.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>