make generic bits/fcntl.h shareable with 64-bit archs

the fcntl file locking command macro values in the existing generic
bits/fcntl.h were the "64" variants, requiring 64-bit archs that use
the "plain" variants to have their own bits/fcntl.h, even if they
otherwise use the common definitions for everything.

since commit 7cc79d10af exposed
__LONG_MAX to all bits headers, we can now make the generic one common
between 32- and 64-bit archs.

arch/generic/bits/fcntl.h

@@ -30,9 +30,15 @@
 #define F_SETSIG 10
 #define F_GETSIG 11
 
+#if __LONG_MAX == 0x7fffffffL
 #define F_GETLK 12
 #define F_SETLK 13
 #define F_SETLKW 14
+#else
+#define F_GETLK 5
+#define F_SETLK 6
+#define F_SETLKW 7
+#endif
 
 #define F_SETOWN_EX 15
 #define F_GETOWN_EX 16