Update linenoise.c: calloc returning NULL is not handled
Update linenoise.c: calloc returning NULL is not handled

Calloc function tries to allocate 4096 bytes.
If such memory is not available, it returns NULL pointer.
This exception was not handled in the code, causing a dirty crash.

espressif/esp-idf,espressif/esp-idf,espressif/esp-idf,espressif/esp-idf