ktest.pl: Fix spelling mistake "Cant" -> "Can't"

There is a spelling mistake in an error message. Fix it.

Link: https://lkml.kernel.org/r/[email protected]

Signed-off-by: Colin Ian King <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>

Author: Colin Ian King

tools/testing/ktest/ktest.pl

@@ -1543,7 +1543,7 @@ sub create_pty {
     my $TIOCGPTN = 0x80045430;
 
     sysopen($ptm, "/dev/ptmx", O_RDWR | O_NONBLOCK) or
-	dodie "Cant open /dev/ptmx";
+	dodie "Can't open /dev/ptmx";
 
     # unlockpt()
     $tmp = pack("i", 0);