Implement common logging function

When used as a library, it's desirable to be able to suppress logging,
or pipe logging through a different path.  This commit changes behavior
such that logging is disabled by default, and introduces 2 new methods,
cper_set_log_stdio and cper_set_log_custom.

These allow library integrators to specify their logging mode.  In
practice, this also allows fuzzing to run faster by not printing errors
to the log.

Change-Id: I941476627bc9b8261ba5f6c0b2b2338fdf931dd2
Signed-off-by: Ed Tanous <etanous@nvidia.com>
diff --git a/sections/cper-section-ccix-per.c b/sections/cper-section-ccix-per.c
index d68f422..a8a5310 100644
--- a/sections/cper-section-ccix-per.c
+++ b/sections/cper-section-ccix-per.c
@@ -11,6 +11,7 @@
 #include <libcper/Cper.h>
 #include <libcper/cper-utils.h>
 #include <libcper/sections/cper-section-ccix-per.h>
+#include <libcper/log.h>
 
 //Converts a single CCIX PER log CPER section into JSON IR.
 json_object *cper_section_ccix_per_to_ir(const UINT8 *section, UINT32 size)
@@ -58,7 +59,8 @@
 						      remaining_length,
 						      &encoded_len);
 			if (encoded == NULL) {
-				printf("Failed to allocate encode output buffer. \n");
+				cper_print_log(
+					"Failed to allocate encode output buffer. \n");
 			} else {
 				json_object_object_add(
 					section_ir, "ccixPERLog",
@@ -120,7 +122,8 @@
 			json_object_get_string(encoded),
 			json_object_get_string_len(encoded), &decoded_len);
 		if (decoded == NULL) {
-			printf("Failed to allocate decode output buffer. \n");
+			cper_print_log(
+				"Failed to allocate decode output buffer. \n");
 		} else {
 			fwrite(decoded, decoded_len, 1, out);
 			fflush(out);