libefiwrapper: use putchar() to send a simple character

Call printf() to write a simple char is overkill.

Change-Id: Ideb99a962d6ec65f06ff87cbf566f7c8e946921a
Signed-off-by: Jeremy Compostella <[email protected]>

Author: jeremy-compostella

include/libefiwrapper/external.h

@@ -78,6 +78,7 @@ int strncmp(const char *s1, const char *s2, size_t n);
 int printf(const char *format, ...);
 int snprintf(char *str, size_t size, const char *fmt, ...);
 int getchar(void);
+int putchar(unsigned int i);
 
 /* libpayload.h */
 void ndelay(unsigned int n);

libefiwrapper/conout.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, Intel Corporation
+ * Copyright (c) 2016-2020, Intel Corporation
  * All rights reserved.
  *
  * Author: Jérémy Compostella <[email protected]>
@@ -45,7 +45,7 @@ conout_output_string(__attribute__((__unused__)) struct _SIMPLE_TEXT_OUTPUT_INTE
 		     CHAR16 *String)
 {
 	while (*String)
-		printf("%c", *String++);
+		putchar(*String++);
 
 	return EFI_SUCCESS;
 }

libefiwrapper/serialio.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, Intel Corporation
+ * Copyright (c) 2016-2020, Intel Corporation
  * All rights reserved.
  *
  * Authors: Jérémy Compostella <[email protected]>
@@ -49,7 +49,7 @@ serialio_write(__attribute__((__unused__)) SERIAL_IO_INTERFACE *This,
 		return EFI_INVALID_PARAMETER;
 
 	for (i = 0; i < *BufferSize; i++)
-		printf("%c", ((char *)Buffer)[i]);
+		putchar(((unsigned char *)Buffer)[i]);
 
 	return EFI_SUCCESS;
 }