x300: Fix invalid GPIO source bank error message

When calling `get_gpio_srcs()` or `get_gpio_src()` with an invalid bank
parameter, the error text associated with the `uhd::runtime_error` that
is thrown prints the expected bank, not the erroneous bank, e.g.:

>>> my_x310.get_gpio_srcs('BAD_BANK', 0)
[ERROR] [X300::MB_CTRL] Invalid GPIO source bank: BAD_BANK. Only supported
bank is FP0
Traceback (most recent call last):
  File "<stdin>", line 2, in <module>
RuntimeError: RuntimeError: Invalid GPIO source bank: FP0

The invalid source bank on the last line should read BAD_BANK, not FP0.

1 files changed, 2 insertions, 2 deletions

diff --git a/host/lib/usrp/x300/x300_mb_controller.cpp b/host/lib/usrp/x300/x300_mb_controller.cpp
index ccbd7c20e..9ef20878e 100644
--- a/host/lib/usrp/x300/x300_mb_controller.cpp
+++ b/host/lib/usrp/x300/x300_mb_controller.cpp
@@ -503,7 +503,7 @@ std::vector<std::string> x300_mb_controller::get_gpio_srcs(const std::string& ba
             "Invalid GPIO source bank: " << bank << ". Only supported bank is "
                                          << GPIO_SRC_BANK);
         throw uhd::runtime_error(
-            std::string("Invalid GPIO source bank: ") + GPIO_SRC_BANK);
+            std::string("Invalid GPIO source bank: ") + bank);
     }
     return {GPIO_SRC_RFA, GPIO_SRC_RFB};
 }
@@ -515,7 +515,7 @@ std::vector<std::string> x300_mb_controller::get_gpio_src(const std::string& ban
             "Invalid GPIO source bank: " << bank << ". Only supported bank is "
                                          << GPIO_SRC_BANK);
         throw uhd::runtime_error(
-            std::string("Invalid GPIO source bank: ") + GPIO_SRC_BANK);
+            std::string("Invalid GPIO source bank: ") + bank);
     }
     uint32_t fp_gpio_src = _zpu_ctrl->peek32(SR_ADDR(SET0_BASE, ZPU_RB_FP_GPIO_SRC));
     const auto gpio_srcs = get_gpio_srcs(bank);