tls: don't abort the connection on signal-interrupted sends

tls: don't abort the connection on signal-interrupted sends

When a signal interrupts a blocking send, tls_tx_records() treats the
resulting -ERESTARTSYS as a transmission failure and marks the socket
errored via tls_err_abort() with the raw error code. Later syscalls
return the kernel-internal errno 512 (ERESTARTSYS) to userspace, as the
signal it stems from is no longer pending during syscall exit and thus
never translated.

An interrupted send is not a connection error: the partially sent record
stays queued and is resent later. Interrupt error codes are therefore
excluded from the abort in the same way as -EAGAIN.

Fixes: b341ca51d267 ("tls: Fix tls_sw_sendmsg error handling")
Signed-off-by: Maximilian Immanuel Brandtner <maxbr@linux.ibm.com>
Link: https://patch.msgid.link/20260805063109.1772314-1-maxbr@linux.ibm.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>