Switch back to rand().

rand_s is broken in AppVeyor.

src/Makefile

@@ -250,13 +250,11 @@ CFLAGS_CROSS_WIN32      += -I$(OPENCL_HEADERS_KHRONOS)/
 CFLAGS_CROSS_WIN32      += -I$(WIN_ICONV_32)/include/
 CFLAGS_CROSS_WIN32      += -m32
 CFLAGS_CROSS_WIN32      += -DWITH_HWMON
-CFLAGS_CROSS_WIN32      += -D_CRT_RAND_S
 CFLAGS_CROSS_WIN64      := $(CFLAGS)
 CFLAGS_CROSS_WIN64      += -I$(OPENCL_HEADERS_KHRONOS)/
 CFLAGS_CROSS_WIN64      += -I$(WIN_ICONV_64)/include/
 CFLAGS_CROSS_WIN64      += -m64
 CFLAGS_CROSS_WIN64      += -DWITH_HWMON
-CFLAGS_CROSS_WIN64      += -D_CRT_RAND_S
 
 LFLAGS_CROSS_LINUX32    := $(LFLAGS)
 LFLAGS_CROSS_LINUX32    += -lpthread

src/shared.c

@@ -381,10 +381,7 @@ u32 get_random_num (const u32 min, const u32 max)
 
   #if defined (_WIN)
 
-  u32 r;
-  rand_s(&r);
-
-  return ((r % (max - min)) + min);
+  return (((u32) rand () % (max - min)) + min);
 
   #else