doc: improve printf(1) reference in echo man page

* src/echo.c (usage): Use printf(1) rather than 'printf',
which is marked up more appropriately, and can be
referenced by some man page readers.
Fixes https://bugs.gnu.org/72914

diff --git a/src/echo.c b/src/echo.c
index 11290f6f1db01569fef7911fc467e3e41f6484e8..4cc269c381dac238be30b2fb0f6946fe26fd2cc4 100644 (file)
--- a/src/echo.c
+++ b/src/echo.c
@@ -82,7 +82,7 @@ If -e is in effect, the following sequences are recognized:\n\
 "), stdout);
   printf (USAGE_BUILTIN_WARNING, PROGRAM_NAME);
   fputs (_("\n\
-Consider using the 'printf' command instead,\n\
+Consider using the printf(1) command instead,\n\
 as it avoids problems when outputting option-like strings.\n\
 "), stdout);
   emit_ancillary_info (PROGRAM_NAME);