Include fcntl.h where needed

I was toying around with a home-made version of include-what-you-use,
which showed that we're missing the include in a number of places.

At the moment it is indirectly resolved via libkmod.h, which pulls said
header for O_TRUNC and O_NONBLOCK. It's unlikely that we'll drop the
include from the public header, although that doesn't mean that aiming
for self-contained sources is a bad idea.

For context: I am looking to remove the libkmod static link to
init-module.so and part of that meant building libkmod-elf.c without
the rest of kmod.

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>

Author: evelikov

libkmod/libkmod-config.c

@@ -7,6 +7,7 @@
 #include <ctype.h>
 #include <dirent.h>
 #include <errno.h>
+#include <fcntl.h>
 #include <stdarg.h>
 #include <stddef.h>
 #include <stdio.h>

libkmod/libkmod-file-zlib.c

@@ -6,6 +6,7 @@
 #define DLSYM_LOCALLY_ENABLED ENABLE_ZLIB_DLOPEN
 
 #include <errno.h>
+#include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>

libkmod/libkmod-file.c

@@ -4,6 +4,7 @@
  */
 
 #include <errno.h>
+#include <fcntl.h>
 #include <limits.h>
 #include <stdbool.h>
 #include <stdio.h>

libkmod/libkmod-index.c

@@ -8,6 +8,7 @@
 #include <assert.h>
 #include <endian.h>
 #include <errno.h>
+#include <fcntl.h>
 #include <fnmatch.h>
 #include <inttypes.h>
 #include <limits.h>

libkmod/libkmod-module.c

@@ -7,6 +7,7 @@
 #include <ctype.h>
 #include <dirent.h>
 #include <errno.h>
+#include <fcntl.h>
 #include <fnmatch.h>
 #include <inttypes.h>
 #include <limits.h>

libkmod/libkmod.c

@@ -6,6 +6,7 @@
 #include <assert.h>
 #include <ctype.h>
 #include <errno.h>
+#include <fcntl.h>
 #include <fnmatch.h>
 #include <limits.h>
 #include <stdarg.h>

tools/depmod.c

@@ -9,6 +9,7 @@
 #include <dirent.h>
 #include <endian.h>
 #include <errno.h>
+#include <fcntl.h>
 #include <getopt.h>
 #include <limits.h>
 #include <regex.h>