dmaengine: ppc4xx: Use scnprintf() for avoiding potential buffer overflow

Since snprintf() returns the would-be-output size instead of the
actual output size, the succeeding calls may go beyond the given
buffer limit. Fix it by replacing with scnprintf().

Signed-off-by: Takashi Iwai <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Vinod Koul <[e-mail]>

drivers/dma/ppc4xx/adma.c

···
 	for (i = 0; i < PPC440SPE_ADMA_ENGINES_NUM; i++) {
 		if (ppc440spe_adma_devices[i] == -1)
 			continue;
-		size += snprintf(buf + size, PAGE_SIZE - size,
+		size += scnprintf(buf + size, PAGE_SIZE - size,
 				 "PPC440SP(E)-ADMA.%d: %s\n", i,
 				 ppc_adma_errors[ppc440spe_adma_devices[i]]);
 	}