Fix embarrassing typo in 1988/phillipps/README.md

... well embarrassing for me ...

1988/phillipps/README.md

@@ -19,7 +19,7 @@ make all
 systems. It did not compile with clang because it requires the second and third
 args to main() to be `char **` but even before that with gcc it printed random
 characters. After fixing it for clang by changing main() to call the new
-function pain() (chosen because it's a paint that clang requires these args to
+function pain() (chosen because it's a pain that clang requires these args to
 be `char **` :-) ) with the correct args it now works. Thank you Cody for your
 assistance!