compile: avoid min macro pollution

The generic min macro in util.h is too common and can conflict with
other libraries. use ccan/minmax in the source files to avoid pollution.

the ccan/minmax will check the type of the input parameters, so cast the
`u8* - u8*` to `int` to avoid the type mismatch.

Before renaming the macro, the cpp's std::min will fail to compile.
```
./test/cpp.cc: In function ‘int min_compile_test()’:
../src/nvme/util.h:563:19: error: expected unqualified-id before ‘(’ token
  563 | #define min(x, y) ((x) > (y) ? (y) : (x))
```

Signed-off-by: Jian Zhang <[email protected]>

src/nvme/ioctl.c

@@ -23,6 +23,7 @@
 #include <sys/time.h>
 
 #include <ccan/build_assert/build_assert.h>
+#include <ccan/ccan/minmax/minmax.h>
 #include <ccan/endian/endian.h>
 
 #include "ioctl.h"
@@ -503,7 +504,7 @@ static int read_ana_chunk(int fd, enum nvme_log_ana_lsp lsp, bool rae,
 	}
 
 	while (*read < to_read) {
-		__u32 len = min(log_end - *read, NVME_LOG_PAGE_PDU_SIZE);
+		__u32 len = min_t(int, log_end - *read, NVME_LOG_PAGE_PDU_SIZE);
 		int ret;
 
 		ret = nvme_get_log_ana(fd, lsp, rae, *read - log, len, *read);

src/nvme/mi.c

@@ -14,6 +14,7 @@
 #include <unistd.h>
 
 #include <ccan/array_size/array_size.h>
+#include <ccan/ccan/minmax/minmax.h>
 #include <ccan/endian/endian.h>
 
 #include "log.h"
@@ -1021,7 +1022,7 @@ static int read_ana_chunk(nvme_mi_ctrl_t ctrl, enum nvme_log_ana_lsp lsp, bool r
 	}
 
 	while (*read < to_read) {
-		__u32 len = min(log_end - *read, NVME_LOG_PAGE_PDU_SIZE);
+		__u32 len = min_t(int, log_end - *read, NVME_LOG_PAGE_PDU_SIZE);
 		int ret;
 
 		ret = nvme_mi_admin_get_log_ana(ctrl, lsp, rae,

src/nvme/util.c

@@ -22,6 +22,7 @@
 #include <netdb.h>
 #include <unistd.h>
 
+#include <ccan/ccan/minmax/minmax.h>
 #include <ccan/endian/endian.h>
 
 #include "cleanup.h"

src/nvme/util.h

@@ -560,8 +560,6 @@ char *kv_keymatch(const char *kv, const char *key);
  */
 char *startswith(const char *s, const char *prefix);
 
-#define min(x, y) ((x) > (y) ? (y) : (x))
-
 #define __round_mask(val, mult) ((__typeof__(val))((mult)-1))
 
 /**

test/cpp.cc

@@ -6,9 +6,15 @@
  * Authors: Keith Busch <[email protected]>
  */
 
+#include <algorithm>
 #include <iostream>
 #include <libnvme.h>
 
+static int min_compile_test()
+{
+	return std::min(1, 2);
+}
+
 int main()
 {
 	nvme_root_t r;
@@ -62,5 +68,7 @@ int main()
 	std::cout << "\n";
 	nvme_free_tree(r);
 
+	min_compile_test();
+
 	return 0;
 }