firmware-utils: pc1crypt: fix compiler warnings/errors
pc1crypt.c:170:12: error: pointer targets in passing argument 1 of ‘strcpy’ differ in signedness [-Werror=pointer-sign]
pc1crypt.c:218:21: error: unused variable ‘board’ [-Werror=unused-variable]
pc1crypt.c:326:26: error: pointer targets in passing argument 2 of ‘pc1_decrypt_buf’ differ in signedness [-Werror=pointer-sign]
pc1crypt.c:328:26: error: pointer targets in passing argument 2 of ‘pc1_encrypt_buf’ differ in signedness [-Werror=pointer-sign]
pc1crypt.c:343:2: error: label ‘out_flush’ defined but not used [-Werror=unused-label]
pc1crypt.c:319:3: error: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Werror=unused-result]
Signed-off-by: Petr Štetiar <ynezz@true.cz>