1. Warnings about "FRU Area Length" based on uninitialized (malloc'd) memory
contents (due to fru->max_read_size not being initialized, left at 0) and
fru_data not being zeroed after malloc() in ipmi_fru_set_field_string().
2. "fru edit" commands for any field index other than 0 would fail (with "Field
not found !" error) due to a couple offset and length calculation errors (for
all the supported "area" types) in ipmi_fru_set_field_string().
3. "fru edit" commands would corrupt the FRU Inventory Area due to incorrect
"source offset" value being specified in write_fru_area() call in
impi_fru_set_field_string().
Commit for Rob Swindell