cmd: conitrace: replace getc() by getchar()

This command was missed when renaming getc() to getchar().

Fixes: c670aeee3df9 ("common: rename getc() to getchar()")
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/cmd/conitrace.c b/cmd/conitrace.c
index 88850db..811f5c6 100644
--- a/cmd/conitrace.c
+++ b/cmd/conitrace.c
@@ -19,10 +19,10 @@
 
 	/* Empty input buffer */
 	while (tstc())
-		getc();
+		getchar();
 
 	for (;;) {
-		int c = getc();
+		int c = getchar();
 
 		if (first && (c == 'x' || c == 'X'))
 			break;