sdm: Use fstream to read sysfs entries.

- Replace FILE operations with fstream templates to read sysfs entries.

CRs-Fixed: 1029997
Change-Id: I5603617cbada01a4651394577bed56de38f9f060
diff --git a/sdm/libs/utils/sys.cpp b/sdm/libs/utils/sys.cpp
index a622b9e..6dddcfb 100644
--- a/sdm/libs/utils/sys.cpp
+++ b/sdm/libs/utils/sys.cpp
@@ -31,6 +31,7 @@
 #include <sys/ioctl.h>
 #include <fcntl.h>
 #include <unistd.h>
+#include <string>
 
 #define __CLASS__ "Sys"
 
@@ -49,46 +50,15 @@
 Sys::poll Sys::poll_ = ::poll;
 Sys::pread Sys::pread_ = ::pread;
 Sys::pwrite Sys::pwrite_ = ::pwrite;
-Sys::fopen Sys::fopen_ = ::fopen;
-Sys::fclose Sys::fclose_ = ::fclose;
-Sys::getline Sys::getline_ = ::getline;
 Sys::pthread_cancel Sys::pthread_cancel_ = PthreadCancel;
 Sys::dup Sys::dup_ = ::dup;
 Sys::read Sys::read_ = ::read;
 Sys::write Sys::write_ = ::write;
 Sys::eventfd Sys::eventfd_ = ::eventfd;
 
-#else
-
-// Point to virtual driver interfaces.
-extern int virtual_ioctl(int fd, int cmd, ...);
-extern int virtual_open(const char *file_name, int access, ...);
-extern int virtual_close(int fd);
-extern int virtual_poll(struct pollfd *fds,  nfds_t num, int timeout);
-extern ssize_t virtual_pread(int fd, void *data, size_t count, off_t offset);
-extern ssize_t virtual_pwrite(int fd, const void *data, size_t count, off_t offset);
-extern FILE* virtual_fopen(const char *fname, const char *mode);
-extern int virtual_fclose(FILE* fileptr);
-extern ssize_t virtual_getline(char **lineptr, size_t *linelen, FILE *stream);
-extern int virtual_dup(int fd);
-extern ssize_t virtual_read(int fd, void *data, size_t count);
-extern ssize_t virtual_write(int fd, const void *data, size_t count);
-extern int virtual_eventfd(unsigned int initval, int flags);
-
-Sys::ioctl Sys::ioctl_ = virtual_ioctl;
-Sys::open Sys::open_ = virtual_open;
-Sys::close Sys::close_ = virtual_close;
-Sys::poll Sys::poll_ = virtual_poll;
-Sys::pread Sys::pread_ = virtual_pread;
-Sys::pwrite Sys::pwrite_ = virtual_pwrite;
-Sys::fopen Sys::fopen_ = virtual_fopen;
-Sys::fclose Sys::fclose_ = virtual_fclose;
-Sys::getline Sys::getline_ = virtual_getline;
-Sys::pthread_cancel Sys::pthread_cancel_ = ::pthread_cancel;
-Sys::dup Sys::dup_ = virtual_dup;
-Sys::read Sys::read_ = virtual_read;
-Sys::write Sys::write_ = virtual_write;
-Sys::eventfd Sys::eventfd_ = virtual_eventfd;
+bool Sys::getline_(fstream &fs, std::string &line) {
+  return std::getline(fs, line) ? true : false;
+}
 
 #endif  // SDM_VIRTUAL_DRIVER