Because it may be needed in public header files, move the definition
of OPENSSL_NO_FP_API on existence of OPENSSL_SYS_MSDOS to e_os2.h.
diff --git a/e_os2.h b/e_os2.h
index 81be302..80ec03e 100644
--- a/e_os2.h
+++ b/e_os2.h
@@ -201,6 +201,7 @@
 
 /* Specials for I/O an exit */
 #ifdef OPENSSL_SYS_MSDOS
+# define OPENSSL_NO_FP_API
 # define OPENSSL_UNISTD_IO <io.h>
 # define OPENSSL_DECLARE_EXIT extern void exit(int);
 #else