lib: libfile: Do not ignore errors in close() ...

Some character devices may perform meaningful operations in their
implementation of close() -- a good example would be socfpga.c which
checks if the FPGA was programmed succesfully in it's close() method
-- so ignoring return value of this call may cause false positives in
checking exit status for success.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

read_file_2(): drop unnecessary 'else' ...

Signed-off-by: Alexander Smirnov <alllecs@yandex.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

libfile: Add copy_recursive ...

To recursively copy a directory tree.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

libfile: add compare_file function ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

read_file_2: Fix return value ...

Set return value correct in error case.
This prevents barebox from crashing in some conditions.

Signed-off-by: Teresa Gámez <t.gamez@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

read_file: introduce read_file_2 ...

read_file has some limitations:

- It is not possible to check the error code since read_file returns
  NULL for failure
- It is not possible to limit the buffer size to sensible limits.

This patch introduces read_file_2 which doesn't have these limitations.
read_file becomes a wrapper around read_file_2.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

move file helper functions to separate file ...

We have our file helper functions in several places. Move them
all to lib/libfile.c.
With this we no longer have file helpers in fs/fs.c which contains
the core fs functions and no functions in lib/libbb.c which are
not from busybox.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>