common: Fix 'unchecked return code' warnings

Several tools are simply not checking return code of functions marked
with 'warn_unused_result'.

Provide wrappers for the read/write functions to avoid patching old
code and providing proper error handling.
Fix the remaining ones (calls to fgets() and system()).

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/misc-utils/docfdisk.c b/misc-utils/docfdisk.c
index 9956de5..b363662 100644
--- a/misc-utils/docfdisk.c
+++ b/misc-utils/docfdisk.c
@@ -275,7 +275,11 @@ int main(int argc, char **argv)
 	show_header(mhoffs);
 
 	printf("\nReady to update device.  Type 'yes' to proceed, anything else to abort: ");
-	fgets(line, sizeof(line), stdin);
+	if (!fgets(line, sizeof(line), stdin)) {
+		printf("Failed to retrieve input chars!\n");
+		return 1;
+	}
+
 	if (strcmp("yes\n", line))
 		return 0;
 	printf("Updating MediaHeader...\n");