Fix incorrect keyword

Author: USLTD

src/pointers/_cstd.py

@@ -24,7 +24,7 @@
     _c_library_name = find_library("c") or "libc.so.6"
 
 dll = ctypes.CDLL(_c_library_name)
-mdll = dll if platform in ("win32", "cygwin") else ctypes.CDLL(find_library("m") else "libm.so.6")
+mdll = dll if platform in ("win32", "cygwin") else ctypes.CDLL(find_library("m") or "libm.so.6")
 
 class tm(ctypes.Structure):
     _fields_ = [