prf.c: remove buffer limitation on field width and padding for integers
prf.c: remove buffer limitation on field width and padding for integers

Zero-padding of integers took place in the on-stack buffer before
justification. Let's perform that padding on the fly while sending
out data instead.

Signed-off-by: Nicolas Pitre <76342682d5afc62854e1102d9578521fe1ed6813@baylibre.com>

zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,finikorg/zephyr,galak/zephyr,nashif/zephyr,finikorg/zephyr,galak/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,nashif/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,finikorg/zephyr,nashif/zephyr,Vudentz/zephyr,galak/zephyr,nashif/zephyr,galak/zephyr,finikorg/zephyr,Vudentz/zephyr