Remove second file system check when growing a partition (#741211)

Shrinking a partition performs a single file system check step, but
growing a partition still performs two file system checks.

    Grow /dev/sda8 from 1.00 GiB to 10.00 GiB
    + calibrate /dev/sda8
    + check file system on /dev/sda8 for errors and (if possible) fix them
    + grow partition from 1.00 GiB to 10.00 GiB
    + check file system on /dev/sda8 for errors and (if possible) fix them
    + grow file system to fill the partition

This is a leftover from the early days of GParted when resizing a
partition used cylinder buffering and performed three file system
checks.  See prior to commit:

    d663c3c277f60da2ac1785c039f25f7920a315e9
    removed cylindersize buffering during resize from the filesystems.

Remove the second file system check when growing a partition.

Bug 741211 - Remove unnecessary duplicate actions when resizing a
             partition
Stop recreating linux-swap twice when shrinking a partition (#741211)

Shrinking swap partition operation performs these steps:

    Shrink /dev/sdb2 from 2.00 GiB to 1.00 GiB
    + calibrate /dev/sdb2
    + check file system on /dev/sdb2 for errors and (if possible) fix them
        checking is not available for this file system
    + shrink file system
      + create new linux-swap file system
        + mkswap -L "test-swap" -U "bd381eba-5df7-42e2-8e0e-411e9701c995" /dev/sdb2
    + shrink partition from 2.00 GiB to 1.00 GiB
      + create new linux-swap file system
        + mkswap -L "test-swap" -U "bd381eba-5df7-42e2-8e0e-411e9701c995" /dev/sdb2

Resizing a linux-swap partition was partially special cased in
GParted_Core::resize().  Make it fully special cased so that it just
does the following steps.  No more skipped file system checks or extra
resizing.

    1)  Resize partition,
    2)  Recreate linux-swap.

This existing call chain recreates the linux-swap:
    GParted_Core::resize_filesystem()
        linux_swap::resize()

A compound move and resize operation still performs unnecessary checks
and recreates of linux-swap, but less than before.

Bug 741211 - Remove unnecessary duplicate actions when resizing a
             partition
Refactor resize() to make it even easier to understand (#741211)

Split the resizing file system and resizing partition calls in
GParted_Core::resize() into separate grow and shrink code paths.

Note that this also changes the degenerative case of calling resize()
when the partition isn't changing size, for non-swap partitions, from a
file system check step to a successful no-op.  This doesn't matter as my
testing never found resize() to be called when the partition isn't
changing size.

Also correct spelling of local variable success.

Bug 741211 - Remove unnecessary duplicate actions when resizing a
             partition