fix log message

src/core/ngx_output_chain.c

diff --git a/src/core/ngx_output_chain.c b/src/core/ngx_output_chain.c
index c4bd678..db7337c 100644
--- a/src/core/ngx_output_chain.c
+++ b/src/core/ngx_output_chain.c
@@ -414,7 +414,7 @@
 
         if (n != size) {
             ngx_log_error(NGX_LOG_ALERT, src->file->log, 0,
-                          ngx_read_file_n " reads only %z of %O from file",
+                          ngx_read_file_n " read only %z of %O from file",
                           n, size);
             if (n == 0) {
                 return NGX_ERROR;

src/os/unix/ngx_files.h

diff --git a/src/os/unix/ngx_files.h b/src/os/unix/ngx_files.h
index 7e84070..1edac54 100644
--- a/src/os/unix/ngx_files.h
+++ b/src/os/unix/ngx_files.h
@@ -58,7 +58,11 @@
 
 
 ssize_t ngx_read_file(ngx_file_t *file, u_char *buf, size_t size, off_t offset);
+#if (NGX_HAVE_PREAD)
+#define ngx_read_file_n          "pread()"
+#else
 #define ngx_read_file_n          "read()"
+#endif
 
 ssize_t ngx_write_file(ngx_file_t *file, u_char *buf, size_t size,
     off_t offset);