Reword the sentence about the required space for the result string.

Closes PR # 1303.-

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/libc/stdio/printf.3 b/lib/libc/stdio/printf.3
index e675b3e..03968af 100644
--- a/lib/libc/stdio/printf.3
+++ b/lib/libc/stdio/printf.3
@@ -645,7 +645,7 @@ and
 .Fn vsprintf
 assume an infinitely long string,
 callers must be careful not to overflow the actual space;
-this is often impossible to assure.
+this is often hard to assure.
 For safety, programmers should use the
 .Fn snprintf
 interface instead.