Fix compiling on i386

Please keep in mind that I did not test the result, but it compiles.

Fixes #131

include/bpftune/bpftune.bpf.h

@@ -205,7 +205,7 @@ unsigned int tuner_id;
 unsigned int strategy_id;
 unsigned int bpftune_pid;
 /* init_net value used for older kernels since __ksym does not work */
-unsigned long bpftune_init_net;
+unsigned long long bpftune_init_net;
 
 /* TCP buffer tuning */
 #ifndef SO_SNDBUF

src/tcp_buffer_tuner.bpf.c

@@ -37,7 +37,7 @@ int kernel_page_size;
 int kernel_page_shift;
 int sk_mem_quantum;
 int sk_mem_quantum_shift;
-unsigned long nr_free_buffer_pages;
+unsigned long long nr_free_buffer_pages;
 
 #define tcp_tunable_corr(__id, __cookie, __newval, __tp, __field_type, __field)\
 	{								\

src/tcp_buffer_tuner.c

@@ -89,7 +89,7 @@ int get_from_file(FILE *fp, const char *fmt, ...)
 	return ret;
 }
 
-long nr_free_buffer_pages(bool initial)
+long long nr_free_buffer_pages(bool initial)
 {
 	unsigned long nr_pages = 0;
 	char *mzone = "Normal";