If there's not enough networking buffers at certain moment,
they might become available later. So instead of closing connection
(and failing assertation) sleep and retry. This avoid the following
assertion failure when there's much of data to send:
net_pkt: Data buffer (1500) allocation failed.
net_tcp: conn: 0x20076024 packet allocation failed, len=1460
shell_telnet: Failed to send -105, shutting down
ASSERTION FAIL [err == 0] @ .../subsys/shell/shell_ops.c:416
os: r0/a1: 0x00000004 r1/a2: 0x000001a0 r2/a3: 0x00000004
os: r3/a4: 0x20044380 r12/ip: 0x00001958 r14/lr: 0x080c9027
os: xpsr: 0x41000000
os: Faulting instruction address (r15/pc): 0x0811ed26
os: >>> ZEPHYR FATAL ERROR 4: Kernel panic on CPU 0
os: Current thread: 0x20045100 (shell_telnet)
os: Halting system
Signed-off-by: Miika Karanki <miika.karanki@vaisala.com>
7c0047263a